天文观测极移运动周期变化的原因解析  

Analiysis on the observed astronomical periodic changes of polar motion

作　　者：宋贯一[1] 

机构地区：[1]河北省地震局,石家庄050021

出　　处：《地球物理学进展》2009年第5期1652-1659,共8页Progress in Geophysics

摘　　要：宋贯一(1991,2006)相继发现日-地之间存在一种奇特的能量(动量)相耦合的自然现象:当太阳辐射光压作用于地表之后,地球表面物质的特殊物理性质会自然地把太阳辐射光压立刻分解为两部分,即P_1和P_2.其中P_1为全球各纬度带内单位海洋和陆地表面接收到的等值光压(P_1为随时间和纬度而变化的变量).在一个回归年的时段内,由P_1在北、南两半球上的不平衡分布激发自转轴摆动,引起转动惯量的变化(该变化是目前所了解到的地球转动惯量的最大变化)并产生极移,该项极移运动的周期为12个月左右.由于P_1在北、南半球上的分布相对赤道是基本对称的和规则的,P_1对自转轴摆动的激发可称谓"规则性激发";P_2为全球各纬度带内单位陆地和海洋表面接收到的光压值之差(P_2为随时间和纬度而变化的变量).在一个回归年的时段内,由P_2在北、南两半球上的不平衡分布激发自转轴摆动而产生的极移运动周期为14个月附近.由于P_2在北、南两半球上的分布相对赤道是不对称和不规则的,P_2对自转轴摆动的激发可称谓"不规则性激发".这种天然存在的力源,恰恰是近百年来世界各国研究地球自转的地球物理学家渴望寻找的那种既能激发自转轴产生自由章动、又使其摆动含有两个不同周期(12个月和14个月)的激发力源.正是这一奇特自然现象的发现,才使长期以来困扰地球物理学领域内的极移、极移所包含两个周期的涨落变化及由此引起的地球自转速度变化等自然之谜得以破解成为可能.本文作者仅对天文观测的极移运动周期及其极移运动所包含的两个周期分量在一定的范围内变化的成因作出了详细的解析,并得出如下结论:(1)极移运动主要是由太阳光压P_1和P_2共同激发引起的.天文观测的极移摆动周期的涨落变化是太阳光压(P_1+P_2)激发自转轴摆动过程中,在空间上自转轴的摆动�In 1991 and 2006, Song discovered a peculiar natural coupled phenomenon between the sun and earth, of which the principle can be summarized as below. While the solar radiation pressure reaching the surface, it can be divided into 2 parts as P1 and P2 through a special physical reaction of earth surface matter instantly, among which the P1 is the equivalent solar pressure accepted between continent and sea all over globe （P1 is a variable depends on time and latitude）. The differential distribution of P1 between North and South Hemisphere within one tropical year is exciting the rotational axis wobble, together with the changes to rotation momentum （the biggest changes of earth rotation momentum, known so far）, and then produces polar motion with the periods of 12 months circa. Referring to the equator, the distribution between North and South Hemisphere of P1 is symmetric and regular, i.e. ＂regular excitation＂. Another factors, P2, is the solar hemisphere of P1 is symmetric and regular, i.e. ＂regular excitation＂. Another factor, P2, the solar pressure difference accepted between the surface of land and sea among latitude over globe, called as ＂irregular excitation＂, for its disequilibrium distribution refer to equator, this irregularity generate 14 months periodic polar motion from the exciting the rotational axis wobble. Such a little bit irregular annual periodic （about 12months） excitation power source, working as a peculiar natural phenomenon is what the world geophysicists looking for a decade years recently, reacts on the rotational axis and creates the possibility of discovery on why such motion of observed polar motion being of two periods, and the solution of its changes. The writer gives detailed analiysis to the motion of polar motion and the reason why tow periodic changes for them, and then conclud below. （1） The polar motion arises from co-excitation of solar pressure, both P1 and P2, which excites the oscillation of rotational axis, with a fluctuation ranges fro

关 键 词：极移 太阳光压 日-地关系 激发机制 钱德勒摆动 

分 类 号：P311[天文地球—固体地球物理学]